And hobert edwin duncan



(No Model.)

' H. L. KNIGHT & H. E. DUNCAN.

DENTAL IMPRESSION GU]? No. 516,310. Patented Mar. 13, 1894,.

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A UNITED STATES PATENT OFFICE.

HENRY L. KNIGHT, OF LE ROY, MINNESOTA, AND HOBERT EDWIN DUNCAN,

OF WEST SUPERIOR, WISCONSIN.

DENTAL IMPRESSION-CUP.

SPECIFICATION forming part of Letters Patent No. 516,310, dated March 13, 1894.

' Application filed June 15,1893. Serial No. 1 (No ode To all whom it may concern..-

Be it known that we, HENRY L. KNIGHT, residing at Le Boy, in the county of Mower and State of Minnesota, and HOBERT EDWIN 5 DUNCAN, residing at West Superior, in the county of Todd and State of Wisconsin, citizens of the United States, have invented certain new and useful Improvements in Dental Impression-Cups; and we do hereby declare to the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improved dental impression cup. Heretofore impression cups have been made of china, metal and rubber. The objection to the iron and glass cups is that they are so hard that they hurt the month while taking an impression, and the rubber ones are very often not rigid enough. All the cups however, are subject to a very serious objection, and that is, that when an impression of the mouth is being taken, it frequently happens that some disease or dis- 2 5 order is transmitted from one person to another, because it is so difficult to thoroughly clean these cups.

The object of our invention is to produce a cup which will avoid all these difficulties 0 and objections.

A further object is to produce a cup which shall be exceedingly cheap, so that it can be thrown away after using once, and one which will be easy to the mouth, but at the same 3 5 time, sufficiently rigid for practical purposes. With these objects in View, our invention consists in providing a dental impression cup formed of papier mach, or other plastic fibrous material.

Our invention consists also in certain details of construction and combination of parts, all of which will be fully described hereinafter and pointed out in the claim.

In the drawings hereunto annexed, and forming a partof this specification, Figure 1,

is a perspective view of our impression cup. Fig. 2, is a sectional view of the same, and Fig. 3, is a sectional view of a modified construction. I Referring to the drawings, A, indicates a dental impression cup adapted for holding plaster of paris while an impression of the mouth is being taken. This cup is made of papier mach, paper board, or other plastic fibrous material, said cup being shaped or molded in suitable dies, and pressed to make the same rigid and water proof. By this means, a cup can be made at very little cost;

it is rigid enough for all purposes, and will not hurt the mouth like an iron or glass cup. It being so cheap, it is intended to be used only once, and then thrown away, thus preventing the transmission of disease, as it is well known that most peoples mouths are often in a delicate condition while being operated upon.

In Fig. 3, we have shown a slightly modified form of cup, in which we may use a softer material, and strengthen the same with a-web of woven wire fabric, which is covered by the.7o plastic material. This woven wire fabricimparts rigidity to the cup, but does not increase, its cost to any extent, as softer and cruder material can be employed.

Having thus described our invention, what we claim is 

